In the thermocouple, cold junction is at $0^{\circ}C$, hot junction is at $t^{\circ}C$. The graph drawn between thermo - emf (E) and temperature of the hot junction (t) is represented by the equation , $E=at+bt^2$. If $ a = -224b$ the neutral and the inversion temperatures of the thermocouple respectively, in degree celsius are :